Cross-site scripting in Roundcube - CVE-2026-26079
Published: February 8, 2026 / Updated: February 12, 2026
Vulnerability identifier: #VU122450
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Green
CVE-ID: CVE-2026-26079
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Roundcube
Affected software:
Roundcube
Roundcube
Detailed vulnerability description
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data when handling CSS files. A remote attacker can send a specially crafted email messages and perform CSS injection attacks.
How to mitigate CVE-2026-26079
Install updates from vendor's website.